Effects of biometrics, location and persistent organic pollutants on blood clinical-chemical parameters in polar bears (Ursus maritimus) from Svalbard, Norway

Embargo until 31 May 2020.In the present study, blood clinical-chemical parameters (BCCPs) were analysed in 20 female and 18 male Svalbard polar bears (Ursus maritimus) captured in spring 2007. The aim was to study how age, body condition (BC), biometrics, plasma lipid content and geographical location may confound the relationship between persistent organic pollutants (POPs) including PCBs, HCB, chlordanes, DDTs, HCHs, mirex and OH-PCBs and the concentrations of 12 specific BCCPs (hematocrit [HCT], hemoglobin [HB], aspartate aminotransferase [ASAT], alanine aminotransferase [ALAT], γ-glutamyltransferase [GGT], creatine kinase [CK], triglycerides [TG], cholesterol [CHOL], high-density lipoprotein [HDL], creatinine (CREA], urea, potassium (K]), and to investigate if any of these BCCPs may be applied as potential biomarkers for POP exposure in polar bears. Initial PCA and O-PLS modelling showed that age, lipids, BC and geographical location (longitude and latitude) were important parameters explaining BCCPs in females. Following subsequent partial correlation analyses correcting for age and lipids, multiple POPs in females were still significantly correlated with HCT and HDL (all p < 0.05). In males, age, BM, BC and longitude were important parameters explaining BCCPs. Following partial correlation analyses correcting for age, biometrics, lipids and longitude in males, multiple POPs were significantly correlated with HCT, ASAT, GGT and CHOL (all p < 0.05). In conclusion, several confounding parameters has to be taken into account when studying the relations between BCCPs and POPs in polar bears. When correcting for these, in particular HCT may be used as a simple cost-efficient biomarker of POP exposure in polar bears. Furthermore, decreasing HDL concentrations and increasing CHOL concentration with increasing POP concentrations may indicate responses related to increased risk of cardiovascular disease. We therefore suggest to further study POP exposure and lipidome response to increase knowledge of the risk of cardiometabolic syndrome in polar bears.acceptedVersio

Relationships Between Persistent Organic Pollutants (POPs) and Plasma Clinical-Chemical Parameters in Polar Bears (Ursus maritimus) from Svalbard, Norway.

In the present study, clinical-chemical parameters in relationship to persistent organic pollutants (POPs) were investigated in plasma samples from polar bears (Ursus maritimus) captured at Svalbard in 2007. The clinical-chemical parameters examined were: hematocrit (HCT), hemoglobin (HB), aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), γ-glutamyltransferase (GGT), creatine kinase (CK), triglycerides (TG), cholesterol (CHOL), high-density lipoprotein (HDLP), creatinine (CREA), urea, and potassium (K). Altered homeostasis of clinical-chemical parameters in plasma may indicate impact on liver, kidney, heart, muscle, bone, metabolism or the endocrine system. Of the twelve clinical-chemical parameters examined in this study, significant association to POPs were found in seven parameters in female polar bears, whereas eight parameters were found in male polar bears. The results indicate that different POPs may exhibit toxic effect to different organs of polar bears. Liver toxicity was indicated by a decrease of hematologic parameters (HCT and HB), a decrease of liver enzymes (ASAT and GGT), and an elevation of metabolites (TG, CHOL, and HDLP) in relation to contaminant concentrations. Further, kidney toxicity was indicated by a decrease of CREA concentrations in relation to contaminant-concentrations, and muscle toxicity by a decrease in CK concentrations in relation to contaminant-concentrations. Continuous exposure to contaminants may therefore result in decreased renal, hepatic, and muscular functions. It is possible that these POP-associated effects may reduce the fitness and survival of polar bears. The results also indicate that clinical-chemical parameters in plasma can be applied as a non-invasive biomarker for toxicity to organs and metabolic homeostasis caused by exposure to POPs in polar bear. Because of the fast response to environmental factors, including POPs, these biomarkers can be used to measure an effect at an early stage, as well as at low exposure concentrations. However, the present study was not designed to evaluate the relationship between cause and effect, and it is important to take into consideration other factors that can affect clinical-chemical parameters when interpreting the results

Effects of biometrics, location and persistent organic pollutants on blood clinical-chemical parameters in polar bears (Ursus maritimus) from Svalbard, Norway

In the present study, blood clinical-chemical parameters (BCCPs) were analysed in 20 female and 18 male Svalbard polar bears (Ursus maritimus) captured in spring 2007. The aim was to study how age, body condition (BC), biometrics, plasma lipid content and geographical location may confound the relationship between persistent organic pollutants (POPs) including PCBs, HCB, chlordanes, DDTs, HCHs, mirex and OH-PCBs and the concentrations of 12 specific BCCPs (hematocrit [HCT], hemoglobin [HB], aspartate aminotransferase [ASAT], alanine aminotransferase [ALAT], γ-glutamyltransferase [GGT], creatine kinase [CK], triglycerides [TG], cholesterol [CHOL], high-density lipoprotein [HDL], creatinine (CREA], urea, potassium (K]), and to investigate if any of these BCCPs may be applied as potential biomarkers for POP exposure in polar bears. Initial PCA and O-PLS modelling showed that age, lipids, BC and geographical location (longitude and latitude) were important parameters explaining BCCPs in females. Following subsequent partial correlation analyses correcting for age and lipids, multiple POPs in females were still significantly correlated with HCT and HDL (all p < 0.05). In males, age, BM, BC and longitude were important parameters explaining BCCPs. Following partial correlation analyses correcting for age, biometrics, lipids and longitude in males, multiple POPs were significantly correlated with HCT, ASAT, GGT and CHOL (all p < 0.05). In conclusion, several confounding parameters has to be taken into account when studying the relations between BCCPs and POPs in polar bears. When correcting for these, in particular HCT may be used as a simple cost-efficient biomarker of POP exposure in polar bears. Furthermore, decreasing HDL concentrations and increasing CHOL concentration with increasing POP concentrations may indicate responses related to increased risk of cardiovascular disease. We therefore suggest to further study POP exposure and lipidome response to increase knowledge of the risk of cardiometabolic syndrome in polar bears